Pour the rubbing alcohol or vinegar into a gallon-sized zip top freezer bag.
Add the food coloring (10 or more drops) and swirl the bag gently to mix the food coloring with the alcohol.
Place the pasta into the bag and seal the bag closed.Toss and shake the bag until the pasta is evenly coated in color. If additional food coloring is needed, add it and continue shaking the bag to coat. If you want to add essential oil, add 1-2 drops at this point.
When the pasta is completely coated, transfer the pasta to a rimmed baking sheet covered with aluminum foil or parchment paper.
Spread the pasta into an even layer and allow to dry for several hours, stirring once.